
products=(
    ("iphone",5000),
    ("macbook",800),
    ("coffee",30),
    ("python book",105),
    ("bicyle",200)
)

money=input("please input your money:")
if money.isdigit():
    money=int(money)
else:
    exit("err..please input a int")
while True:
    for i,v in enumerate(products,1):
        print(i,">>>>",v)
    cmd=input("which do you want to buy:")
    if cmd=="quit":
        break
